Fix error when ProxyCreds is set to none
Fix error when ProxyCreds is set to none

Fix following error:
(Empire: stager/multi/launcher) > execute
[!] Exception: list index out of range

wisdark/Empire,wisdark/Empire,byt3bl33d3r/Empire,PowerShellEmpire/Empire,adaptivethreat/Empire,wisdark/Empire,EmpireProject/Empire,ThePirateWhoSmellsOfSunflowers/Empire,bneg/Empire,adaptivethreat/Empire,PowerShellEmpire/Empire,bneg/Empire,bneg/Empire,ThePirateWhoSmellsOfSunflowers/Empire,byt3bl33d3r/Empire,EmpireProject/Empire,PowerShellEmpire/Empire,byt3bl33d3r/Empire,EmpireProject/Empire,bneg/Empire,EmpireProject/Empire,ThePirateWhoSmellsOfSunflowers/Empire,ThePirateWhoSmellsOfSunflowers/Empire,EmpireProject/Empire,adaptivethreat/Empire,byt3bl33d3r/Empire,bneg/Empire,wisdark/Empire,EmpireProject/Empire,byt3bl33d3r/Empire,wisdark/Empire,ThePirateWhoSmellsOfSunflowers/Empire